482 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
a portion is thrown over on the ground, for its improvement, but injurious material, such 
as starfish, drills, or other ‘‘rubbish,” is carefully taken away and deposited where it 
can do no harm. 
To wash the oysters, which is often done on the ground, the dredge is brought 
near the surface and before being taken on board it is raised and lowered several 
times, thus washing out the mud, sand, etc. Years ago there was much difficulty in 
doing this, since a positive clutch was used on the drum upon which is wound the 
dredge chain, and the latter could not easily be released; now this trouble is obviated 
by the use of a friction clutch. 
There appears to be considerable variation in the capacity of dredges. Oapt. 
Peter Decker says the dredges he uses on his new steamer “weigh 100 pounds, 
and a full bag will bring in 5 bushels.”* Another authority states that the caiiacity 
of the average steamer’s dredges is 10 to 12 bushels. There are few dredges that will 
dump 30 bushels. t 
Oysters raised by the Poquonock method are lifted, bushes and all, by derricks.^ 
’ Vll.— UNFAVORABLE CONDITIONS, ENEMIES, ETC. 
37. Injury by unfavorable iveather . — Among the agencies tending to check the pros- 
perity of the oyster industry in Long Island Sound, adverse weather during the spawn- 
ing season may undoubtedly be given precedence. Warm, sunny weather is neces- 
sary to the life and healthy growth of the oyster spat; and to obtain a “set” is essential 
to financial success. Sometimes, even after an excellent “set” has been obtained, the 
young oysters are “ winterkilled” — destroyed by the low temperature of the water 
in exceptionally cold weather. In many cases, when not killed, they are left in such 
a weakened condition in the spring that they are easily destroyed by enemies. To 
prevent this the oysters are often moved, before the weather becomes too cold, and 
planted in deep water, where they will not be affected by sudden changes of tem- 
perature. 
In autumn and winter heavy gales frequently blow through the Sound with great 
force, particularly from the eastward. At such times the sea is heavy, and sweeps 
over the shallow oyster beds with destructive force. It is common, after a heavy 
easterly gale, to find the beaches strewn with windrows of oysters ; frequentlj'^ the 
oysters are smothered on the grounds by an accumulation of sand and mud. When 
oysters are washed out upon the shores the only remedy is to take them up and replant 
them. If this can be done in time they will be saved. Oysters planted in deep water 
are not liable to disasters of this kind, since beds at a depth of 35 feet or thereabouts 
are not usually affected by storms. 
A study of the oyster question leads to the conclusion that there is a remarkable 
coincidence between years of moderately warm, clear weather, and subsequent seasons 
of exceptional abundance of oysters. 
38. hijury by mud . — Although the development of the oyster is advanced by its 
.vicinity to muddy bottom, injury through the influence of mud is one of the dangers 
to which it is liable. If, for instance, the infant oyster encounters the slightest film 
‘ Report of Connecticut Bureau of Labor Statistics, p. 126. 
t/&.,p. 127. tI6.,p. 112. 
